MANEJO COM HERBICIDAS EM PRÉ E PÓS-EMERGÊNCIA DA CULTURA DO GERGELIM

Abstract

Sesame is the oldest oilseed cultivated in the world by humanity. However, in the literature, it is noticeable that there is a lack of scientific work that could help the implementation of this crop on a large scale, that is, the mechanization of this crop from planting, handling to harvesting, since this crop has always been managed in a manually, from planting to harvesting. Despite this, the expansion of large planted areas in recent years requires the mechanization of this entire process and, therefore, the objective of this work was to evaluate the effectiveness of herbicides applied in pre- and post-emergence for the control of weeds in sesame crops. An experiment was therefore set up in the experimental field of the IFMT in Campo Novo do Parecis-MT. The experiment was conducted in the field from march to may 2023, with the evaluation of different doses of diuron in post-emergence of the sesame crop: 0; 500; 750 and 1000 g ha-1 of the active ingredient (a.i.), combined with two preemergent herbicides, with two doses each: clomazone (500 g ha-1 of a.i.); clomazone (750 g ha-1 a.i.); S-metolachlor (960 and 1440 g ha-1 a.i.); in addition to a control treatment (without pre-emergents) on seeds previously treated with 1.5 l/ 100 kg of seed, of permit. Visual assessments were carried out, assigning damage and quantitative scales submitted to analysis of variance and comparison between means using the Tukey test at 5%. The diuron herbicide applied post-emergence, starting at a dose of 1.0 L ha-1 of the commercial product, reduces sesame productivity in relation to the untreated crop. S-metalachlor, when applied pre- emergence, even in doses of 960 g ha-1 of the active ingredient, slows down the growth of sesame plants and reduces the stand despite not causing visible damage to phytoxicity. The number of pods per plant and the mass of a thousand sesame grains are not altered by the use of s-metalachlor and clomazone in pre-emergence, combined or not with different doses of diuron, when compared to treatments without herbicides